This invention relates to a process for preparing phosphor pattern for a field emission display panel, a photosensitive element for a field emission display panel, a phosphor pattern for a field emission display panel and a field emission display panel.
In the prior art, as one of flat plate display panels, there has been known a field emission display panel (hereinafter referred to as xe2x80x9cFEDxe2x80x9d) which enables multi-color display panel by providing a phosphor which emits light by colliding thereto electrons emitted from metal surface or a semiconductor surface while applying an electric field.
In recent years, accompanying with the progress of a semiconductor fine patterning technique, a number of fine field electron-emitting emitters can be formed on a Si wafer or a glass substrate with good reproducibility.
According to this progress, field emission can be realized by applying a voltage with several ten volts without applying a high voltage.
FED is a display element in which a cathode substrate to which emitters are formed and an anode substrate to which a fluorescent surface is formed are opposed to each other in a vacuum sealed apparatus and which emits light by electron beam excitation.
FED can be called as a flat CRT having a number of plane electron guns on a flat plane, and in view of many advantages of a thickness of about 2 mm, spontaneous light displaying quality as that of CRT, a wide view filed angle of about 170xc2x0, a quick response rate of xcexcsec order, environmental resistance as that of a vacuum tube and a low consumed power not more than TFT-LCD, it has been expected to use as a wide screen display panel.
In the prior art, as a method for forming the phosphor, a method of coating a slurry liquid or a paste in which phosphors of the respective colors are dispersed is coated by a printing method such as screen printing has been proposed and disclosed in Japanese Provisional Patent Publications No. 115027/1989, No. 124929/1989, No. 124930/1989 and No. 155142/1990. It has also been known that an adhesive property of a specific portion is changed and a portion to which a phosphor is to be adhered is selected whereby three colors of R, G and B are separately formed.
However, the above-mentioned phosphor-dispersed slurry liquid is a liquid state so that dispersion failure is likely caused by sedimentation of phosphors, etc. Also, when a liquid state photosensitive resist is used as the slurry liquid, there is a defect of markedly lowering in preservation stability with the progress of dark reaction. Moreover, to cope with enlargement of a screen and making a fine pattern, these methods involve problems that they cannot realize uniformity in the screen in view of dimensional accuracy and mechanical precision.
An object of the present invention is to provide a process for producing a phosphor pattern for a field emission display panel in which a phosphor pattern for a field emission display panel can be formed on a substrate such as a substrate for forming a phosphor layer for a field emission display panel on which a conductive layer is formed with good mass productivity, high precision and uniform shape.
Another object of the present invention is to provide a process for preparing a phosphor pattern for a field emission display panel with excellent workability and environmental safety.
Further object of the present invention is to provide a process for producing a phosphor pattern for a field emission display panel which is restrained from decreasing in a film thickness and excellent in photosensitivity.
Still further object of the present invention is to provide a photosensitive element for a field emission display panel which is excellent in restraint of edge fusion and handling property, and can form a phosphor pattern having high precision, uniform shape and excellent photosensitivity with good workability.
Still further object of the present invention is to provide a phosphor pattern for a field emission display panel having high precision, uniform shape and excellent in luminance.
Still further object of the present invention is to provide a field emission display panel provided with a phosphor pattern for a field emission display panel having high precision, uniform shape and excellent in luminance.
The first invention relates to a process for preparing a phosphor pattern for a field emission display panel which comprises the steps of: (I) forming (A) a photosensitive resin composition layer containing a phosphor on a substrate to which a conductive layer is formed; (II) selectively irradiating active light to (A) the photosensitive resin composition layer containing a phosphor (III) selectively removing (A) the photosensitive resin composition layer containing a phosphor to which active light has been selectively irradiated by development to form a pattern; and (IV) calcining the pattern to remove unnecessary portion to form a phosphor pattern.
The second invention relates to a process for preparing a phosphor pattern for a field emission display, wherein the step (I) is
(Ia) a step of
placing a photosensitive element having (A) a photosensitive resin composition layer containing a phosphor formed on a support film on the substrate to which a conductive layer is formed so as to contact (A) the photosensitive resin composition layer containing a phosphor with the substrate to which a conductive layer is formed and
applying a pressure to (A) the photosensitive resin composition layer containing a phosphor to laminate (A) the photosensitive resin composition layer containing a phosphor on the substrate to which a conductive layer is formed.
The third invention relates to a process for preparing a phosphor pattern for a field emission display, wherein the step (I) is
(Ib) a step of
placing, on a substrate to which a conductive layer is formed, (B) a filling layer on (A) a photosensitive resin composition layer containing a phosphor and in such a state,
applying a pressure to (B) the filling layer to laminate (A) the photosensitive resin composition layer containing a phosphor and (B) the filling layer on the substrate to which a conductive layer is formed, and (Ic) a step of removing (B) the filling layer.
The fourth invention relates to a process for preparing a phosphor pattern for a field emission display, wherein the step (I) is
(Ibxe2x80x2) a step of
placing a photosensitive element having (B) a filling layer on a support film and (A) a photosensitive resin composition layer containing a phosphor thereon on the substrate to which a conductive layer is formed so as to contact (A) the photosensitive resin composition layer containing a phosphor with the substrate to which a conductive layer is formed and
applying a pressure to (B) the filling layer to laminate (A) the photosensitive resin composition layer containing a phosphor and (B) the filling layer on the substrate to which a conductive layer is formed, and (Ic) a step of removing (B) the filling layer.
The fifth invention relates to a process for preparing a phosphor pattern for a field emission display panel, wherein the respective steps of (I) to (III) are repeated to form a multi-colored pattern comprising photosensitive resin composition layer containing phosphors which are colored to red, green and blue, and then subjecting to the step of (IV) to form a multi-colored phosphor pattern.
The sixth invention relates to a process for preparing a phosphor pattern for a field emission display panel, wherein the respective steps of (I) to (IV) are repeated to form a multi-colored pattern comprising photosensitive resin composition layer containing phosphors which are colored to red, green and blue.
The seventh invention relates to a process for preparing a phosphor pattern for a field emission display panel, wherein (A) said photosensitive resin composition layer containing a phosphor contains:
(a) a polymer having a film-forming property,
(b) a photopolymerizable unsaturated compound having an ethylenically unsaturated group,
(c) a photoinitiator forming a free radical by irradiation of active light, and
(d) a phosphor.
The eighth invention relates to a photosensitive element for a field emission display panel having (A) a photosensitive resin composition layer containing a phosphor on a support film.
The ninth invention relates to a photosensitive element for a field emission display panel, wherein said element has (B) a filling layer on a support film, and (A) a photosensitive resin composition layer containing a phosphor on (B) the filling layer.
The tenth invention relates to a phosphor pattern for a field emission display panel, wherein (A) said photo-sensitive resin composition layer containing a phosphor contains:
(d) a polymer having a film-forming property,
(e) a photopolymerizable unsaturated compound having an ethylenically unsaturated group,
(f) a photoinitiator forming a free radical by irradiation of active light, and
(d) a phosphor.
The eleventh invention relates to a phosphor pattern for a field emission display panel which is prepared by the above-mentioned processes.
The twelfth invention relates to a field emission display panel which is provided with the phosphor pattern for a field emission display panel.